1. Field of the Invention
This invention is in the area of hook-and-loop fastener strips, specifically a hook or loop fastener strip with vertical sealing members located along side edges of a fastener layer. This invention is also in the area of a method for integrally molding the fastener strip with an object, such as a foam-molded product like a cushion body used for an automobile seat. The vertical sealing members form an effective seal against fouling of the hooks or loops when the strip is in-molded into the object.
2. Description of the Related Art
It can be appreciated that an automobile seat is so constructed that its cushion body is covered with a surface material and adopts a recessed shape in order that a passenger can maintain a sitting posture and not feel tired even after sitting for a long time. In a seat having such a recessed shape, a foam-molded product, in which a fastener strip is anchored in a recessed portion thereof as shown in FIG. 29, is employed both as a cushion body and as a means of preventing the surface material from shifting on the recessed portion. By engagement between fastening elements of the fastener strip anchored in the cushion body and mating fastening elements mounted on the surface material, the surface material is prevented from shifting.
For manufacturing the cushion body with which the fastener strip is integrated, the fastener strip is placed in a predetermined mold in such a manner that its fastening element-side face opposes a mold face and then, foam resin material is poured into the mold. By urging the foam resin material to be foamed, the foam-molded product with which the fastener strip is integrated is produced.
At the time of molding, the foam resin may penetrate between the fastening elements of the fastener strip so as to foul the fastening elements, thereby reducing its engaging function.
Various means of sealing the hooks or loops of an in-molded fastener strip against fouling during the molding process are known in the art. Among the different sealing means that have been disclosed are the following:
Foam strips located along the sides of the fastener layer are shown in U.S. Pat. Nos. 5,500,268 and 5,614,045, both to Billarant. In addition, a foam layer which forms a perimeter seal around the hook or loops is disclosed in U.S. Pat. No. 5,766,723 to Oborny.
Plastic ridges which form a seal against the walls of the mold recess are shown in U.S. Pat. No. 5,900,303 to Billarant and U.S. Pat. No. 5,688,576 to Ohno et al. Similar flexible sealing lips, located along each side of the fastener strip, are disclosed in U.S. Pat. No. 5,061,540 to Cripps et al.
A different approach is taken by U.S. Pat. No. 4,693,921 to Billarant et al., U.S. Pat. No. 5,766,385 to Pollard et al., and U.S. Pat. No. 4,563,380 to Black et al.; wherein a protective cover in the form of a film or tape is placed over the hook or loop elements, and then that protective cover is removed after the molding process is complete.
Japanese Utility Model publication No.HEI4-53685 and Japanese Utility Model publication No.HEI6-37712, for example, have disclosed sealing means in which in order to prevent fouling of the fastening elements as mentioned above, a belt-like body or a fastening member is formed on each of both end portions of a fastener strip so as to prevent penetration of foam resin to a surface with the fastening elements. Further, Japanese Patent Application Laid-Open No.SHO60-179003 discloses sealing means in which the fastening elements are entirely covered with a film so as to prevent penetration of the foam resin to the area of the fastening elements during the molding.
In situations where the belt-like body or the fastening member is formed on each of the end portions of the fastener strip, the anchoring force between the fastener strip and a molded product decreases although the penetration of the foam resin into the area of the fastening elements is prevented. Therefore, as in Japanese Utility Model Publication No.HEI4-53685, it is necessary to further attach an anchoring member on a rear face of the fastener strip and fasten this anchoring member to the molded product so as to prevent reduction of the anchoring force between the fastener strip and the molded product. Further, in the case of Japanese Utility Model Publication No.HEI6-37712, the fastening member is composed of unwoven cloth, so that the foam resin is absorbed in this unwoven cloth so as to anchor the fastener strip to a molded product.
In the case of Japanese Patent Application Laid-Open No.SHO60-179003, when the molded product is taken out of a molding die after molding is finished, it is necessary to remove the film, which covers the fastening elements. If such a film is employed, that is to be melted by heat when the foam resin is foamed, non-melted film remains on the fastening elements as a residue thereby leading to reduction of the engaging force.
As for the production method for the foam-molded product in which the fastener strip is molded integrally in the foam-molded product, it is conventionally known that a recess for accommodating the fastening elements of the fastener strip can be formed in a molding die face in order to prevent the foam resin from invading into the area of the fastening elements of the fastener strip, so that the recess blocks the foam resin from invading into the area of the fastening elements, as shown in Japanese Patent Application Laid-Open No.HEI1-163019.
The majority of the above methods, however, exhibit a major disadvantage in that the sealing means are not formed of one piece with the fastener layer, but rather are formed from a different material which is later attached to front of the fastener layer. This increases manufacturing cost and complexity vs. a fastener strip which has its sealing means integrally formed of one piece with the fastening layer.
In addition, the prior art which employs a protective cover to prevent fouling has a further disadvantagexe2x80x94the cover must be removed after molding is completed, introducing an often messy and time-consuming extra step into the molding process.
Accordingly, several objects and advantages of the invention are:
The vertical members which form the anti-fouling seal can be easily formed of one piece with the rest of the fastener layer, using commonly available forming dies or wheels. This reduces steps and cost in the manufacturing process.
The vertical members permit a controlled amount of penetration by the foam as it cures, such that some degree of anchoring of the fastener strip to the object being molded is achieved. Indeed, the spacing of the vertical members can be varied to allow greater foam penetration at the outer edges of the strip, for optimal anchoring; and minimal to no penetration at some distance inward from the edges, for optimal sealing.
The non-continuous nature of the vertical membersxe2x80x94that is, they do not form a continuous stiff wallxe2x80x94allows the edges of the fastener strip to flex if needed along their length, to accommodate curved or uneven mold surfaces and still seal well.
Further objects and advantages of the invention will become apparent from a consideration of the drawings and ensuing description.
The present invention is a fastener strip having a hook or loop, in which vertical sealing members arranged in line with a predetermined interval, are provided. The aforementioned vertical members are preferred to be disposed in a staggered manner in a lengthwise direction. The vertical members form an effective seal against fouling of the hooks or loops when the strip is in-molded into an object.
To achieve the above objective, according to a first aspect of the present invention, there is provided a fastener strip to be integrated with a surface of a foam-molded product for attaching a surface material, the fastener strips comprising vertical members formed on both side edge portions of a surface of a flat substrate made of thermoplastic resin along a length thereof, and a plurality of fastening elements formed in an area surrounded by the vertical members, wherein the vertical members are arranged in at least one row in the length direction, and a gap allowing passage of foam resin is formed between adjacent vertical members.
In this fastener strip, the vertical members are provided on each side edge and are arranged in at least one row in the length direction. The vertical members have the function of restricting penetration of the foam resin into a region inside the vertical members where a plurality of the fastening elements are formed, as well as the function of anchoring the foam resin, which invades through the gaps between the adjacent vertical members and surrounds the vertical members. According to the present invention, not only can the structure of the fastener strip be simplified, but also the function of anchoring the fastener strip to a molded product without using any additional anchoring member can be improved.
Preferably, each of the gaps between the adjacent vertical members is formed as an aisle of a predetermined length in the passage direction of foam resin, so that the penetration of the foam resin into the area of the fastening elements through the aisle is restricted. Consequently, the fastener strip has the function not only of restricting the amount of penetration of the foam resin into the area of the fastening elements due to resistance in the aisle, but also the function of anchoring the fastener strip firmly by increasing the contact area between the foam resin and the vertical members.
Further, preferably, the aisle has a stopper portion. Specifically, the fastener strip has an aisle with the stopper portion having a small gap, that is, the aisle is blind. The stopper portion can prevent the penetration of the foam resin into the area of the fastening elements. Further, such a blind portion allows the vertical member to exert its function as an anchoring member.
Preferably, the substrate and the vertical members or the substrate, vertical members and fastening elements are molded integrally with thermoplastic resin. Because the substrate and vertical members or the substrate, vertical members and fastening elements are formed integrally with thermoplastic resin such as polyester, polyamide, polypropylene, polyvinyl chloride, the fastener strip can be manufactured continuously.
A portion of the fastening elements formed inside the vertical members may also function as anchor members for the foam resin passing through the gap. The foam resin passing, the aforementioned gaps is restricted from invading further by a portion of the fastening elements formed inside the vertical members.
Preferably, at least two rows of the vertical members are provided on each edge portion of the substrate along the length thereof, and at least two rows of the outermost vertical members disposed on each side edge are arranged in line along the length of the fastener strip, while the vertical members in an inner row adjacent the outer rows of vertical members are disposed in a staggered manner.
By disposing two rows of the vertical members in a staggered manner, the foam resin passing through the gaps between the outer vertical members is interrupted by the inner wall portions so that its flow is changed to the right and left directions. Consequently, the foam resin intending to pass the gaps between the inner vertical members is restricted. Further, the foam resin makes contact with the front and rear faces of the outer vertical members so that the vertical members are anchored further firmly by the foam resin.
It is permissible that at least two rows of the vertical members are provided on each side edge along the length and at least one of the outermost rows of vertical members disposed on each side edge includes a plurality of vertical members along the length thereof, while the vertical member located inside the outermost row of vertical members is continuous.
The foam resin, having passed the gaps between the vertical members while being restricted by the outside wall, is prevented from invading into the area of the fastening elements by the continuous vertical member located inside.
Preferably, a plurality of fastening element groups are formed along the length of the substrate surface and each of the fastening element groups is surrounded by at least one vertical member and transverse wall portions. Thus, a plurality of the fastening element groups are defined along the length of the substrate surface, and each fastening element group is surrounded by the at least one vertical member and the transverse wall portions so as to restrict the penetration of the foam resin into the area of the fastening elements.
Each of the aforementioned transverse walls adjacent the fastening element groups may be formed of either a continuous vertical member or plural intermittent vertical members disposed with an interval. The continuous vertical members or intermittent vertical members surrounding the fastening element groups can reliably prevent the foam resin passing the vertical members located on both side edges from invading into the area of the fastening elements.
If the surface of the molding die for manufacturing a foam-molded product is flat, the heights of the aforementioned vertical members and the transverse walls are preferred to be larger than that of the fastening elements. When a surface fastener is placed on the surface of the molding die, the vertical members and the transverse walls make tight contact with the surface of the mold, so that there is no gap between the vertical members/transverse walls and the surface of the mold. Consequently, the penetration of the foam resin into the area of the fastening elements through the gaps between the vertical members and the surface of the mold can be prevented effectively.
If recesses for receiving the fastening elements are formed in the surface of the mold for producing a foam-molded product, the heights of the vertical member and transverse walls may be smaller than that of the fastening elements. When a surface fastener is placed on the surface of the mold, the groups of the fastening elements fit down into the recesses in the surface of the molding die, so that the vertical members and the transverse walls come into firm contact with the surrounding of the recess portion. Consequently, there is no gap formed between the vertical members/transverse walls and the mold. Thus, the penetration of the foam resin through the gaps between the vertical members/transverse walls and the surface of the mold can be prevented effectively.
If a magnet is buried in the mold, it is preferable that at least part of the substrate, fastening elements and vertical members contain magnetically attractable powder of alloy such as iron, cobalt, nickel or the like. When the fastener strip is placed on the surface of the mold for manufacturing a foam-molded product, the fastener strip can be positioned and anchored at an appropriate position of the mold due to magnetic attraction between the magnetically attractable powder in the fastener strip and the magnet provided in the mold. Further, the fastener strip is prevented from moving from said position when the foam resin is foamed, so that no gaps are made between the vertical members and the surface of the mold.
At least a rear face of the substrate can be provided with a magnetically attractable body. The magnetically attractable body to be provided on the fastener strip may include a metallic thin piece of alloy such as iron, cobalt, nickel or the like, a magnetically attractable tape, knitted cloth or unwoven cloth made of metallic fiber or resin fibers mixed with magnetically attractable powder. These materials can be provided at a position where a magnetically attractable body is provided, such as a rear face or a front face of the substrate. It is preferable to provide the magnetically attractable body on the rear face of the substrate in order to simplify the manufacturing process or the structure of the mold. This magnetically attractable body may be a resin layer mixed with magnetically attractable powder of iron, cobalt, nickel or the like. This resin layer is formed on the rear face of the substrate by bonding or coating using an appropriate means such as resin adhesive agent, resin coating or the like.
At least part of the substrate, fastening elements and vertical members may be formed of thermoplastic resin mixed with magnetically attractable powder. Alternately, a magnetically attractable laminate layer or a magnetically attractable coating film containing magnetically attractable powder may be formed at least on the top faces of the vertical members.
The present invention is preferably applied to the case where the foam-molded product is a cushion body for an automobile. In the cushion body of an automobile seat or the like, the foaming-molded product is used as a pad in the cover. The fastener strip is anchored to the cushion body made of the foam-molded product and is coupled with mating fastening elements provided on the cover. As a result, installation and removal of the cover with respect to the cushion body are facilitated.
According to another aspect of the present invention, there is provided a method for molding a surface fastener integrally with a surface of a foam-molded product with the fastening elements of the fastener strip exposed outside. The fastener strip is placed with the fastening elements and the vertical members opposing the surface of the mold and positioned at an appropriate position. Then, foam resin material is poured into the mold and allowed to invade into gaps between adjacent vertical members, and the foam resin material is foamed so as to form a foam-molded product. As a result, the fastener strip is anchored integrally with the surface of the foam-molded product.